Solid state batteries tend to be safer than other batteries.

Here is ProLogium's solid state battery failing to fail after it's been shot with a bullet: https://www.youtube.com/watch?v=ZOubFHO1I3o

Here is Ionic Materials' solid state battery failing to fail after it's been cut with scissors: https://www.youtube.com/watch?v=m9-cNNYb1Ik

I imagine fairly similar to what happens with a gas/petrol vehicle, similar amount of energy to release. Maybe with a bunch more toxic fumes...